Case management is a critical component of services that have developed over the past two decades for people with severe mental disorders. Several models of case management have been articulated. All of these focus significantly on the tasks and functions that case managers need to perform in behalf of the client, and performance of these activities relies heavily on development of a satisfactory collaborative relationship between case manager and client. Importance of the formation of this alliance is acknowledged implicitly or specified explicitly across all major models. However, the client-case manager relationship per se has not been adequately defined and studied. Concepts and measures of the helping relationship in psychotherapy have limited applicability to this service. Adequate definition and measurement of the case management alliance will enhance the capacity to monitor and improve implementation of service interventions in which case management plays a central and significant role. The goal of the proposed work is to develop and validate a measure for use in services research that will improve this capacity to measure and optimize client-case management alliances, both for more rapidly stabilizing clients in the community and ultimately for long-term outcome. The proposed study will entail several major components. First, the construct of case management alliance will be carefully defined and quantified in a preliminary item set. Definition will draw on a range of qualitative and quantitative sources, including previous and preliminary work with existing instruments. Consultation for conceptualization and instrument development will come from clinicians and services researchers with significant experience in the definition and measurement of case management, as well as from consumers. Second, items will be evaluated in a cross-sectional study of 500 case manager-client dyads, and a reliable measure of case management alliance will be derived and evaluated for construct and discriminant validity. Third, the measure will be evaluated against two-year outcomes for predictive validity in a prospective, longitudinal study with 180 dyads. Consumers and providers in both rural urban settings in New Hampshire and Washington, D.C. will provide data for instrument development and validation. Final analysis will evaluate the contribution of case management alliance to focal, intermediate-range outcomes, such as stabilization of housing, substance use, disruptive consequences of symptoms, and engagement in both treatment and community, and will also address the time of development of alliance and its relevance to other outcome domains.